• S12 - IS                Indoor (Water) Temperature Sensor c/w 3" immersion
                              well and enclosure
• S12 - OS              Outdoor Temperature Sensor c/w enclosure
• S12 - SFM          24 Vac, 40Va control transformer
• S12 Manual

• S12 - SENSOR      Temperature Sensor Element
• S12 - OSW            Outdoor Temperature Sensor in a sealed
                               weatherproof enclosure
• S12 - LOCK           Control parameter editing lock - mounts on S12
• S12 - KEY             Control parameter editing key
• S12 - CLK              Night Setback 7-Day programmable time clock
• S12 - FLOW           System pump Flow indication switch
• S12 - XRF               24 Vac, 40Va control transformer